In recent days, the coasts of Canary Islands have been invaded by an “unprecedented” visit of peculiar brown algae with small vesicles, known as sargassum. The immense masses of macroalgae that have covered some bathing areas, such as Valleseco in Santa Cruz de Tenerife or Playa de la Nea in El Rosario, have reached the Archipelago dragged from the Sargasso Sea near the coasts of Florida. And they have not come alone. The seaweed patches have brought crabs, small fish, imperceptible invertebrates, and even tropical coconuts to the Canary shores. Although this is not the first time these algae have appeared in the Canary Islands, researchers state that never before has the arrival of such a quantity been recorded, nor for such a long time.
Since mid-March, these large brown patches have appeared in various parts of the Archipelago, especially those that, due to their orientation, usually suffer from the arrival of debris (such as microplastics). The west of La Palma, El Hierro, Playa de la Nea in Radazul (El Rosario), the west of Tenerife, or Santa Cruz have been some of the places where researchers have spotted these Caribbean-origin patches of seaweed.
These macroalgae, scientifically known as Sargassum, originate from the Sargasso Sea. This area, lost in the middle of the North Atlantic and close to the coasts of Florida – popularly known as the marine Bermuda Triangle – is a region of calm waters named after the large blooms of these algae that occur there. The area covers approximately 1,100 kilometres and does not touch any coast.
Location of the Sargasso Sea, where these macroalgae emerge. / Wikipedia
Back in 1942, Christopher Columbus encountered, while searching for the Indies, a vegetable patch like the one seen this week on the beach of Valleseco in Madeira. The phenomenon had such an impact on him that he even feared his ship could run aground due to the presence of these macroalgae. That moment went down in the history of science as the first to describe this species, but also for revealing the historical connection of the arrivals of these rare macroalgae with the Macaronesia.
